Every job requires the right electrical boxes. There are thousands available, each with a specific purpose. For general work, one style of box is incredibly useful and solves a lot of problems before they arise. That is the adjustable electrical box.
Boxes for Variable Finishes
Adjustable boxes are designed for two cases. The first is for old work when you don’t know how thick the substrate is. In those cases, you either need an adjustable box, or you have to cut the wall and measure the thickness.
The more common use case is for variable wall finishes. If you are installing new work boxes and don’t know what finishes will be on the wall when all is said and done, then an adjustable box is the solution. It can change its wall depth after installation. You simply adjust a screw or slider once the tile, paneling, wainscoting or other finish is installed.
A Quick Installation Guide
New work adjustable boxes are very easy to use. You start by mounting the box to a stud. Depending on the type of box, you will have an adjustable screw or sliding bracket that allows you to adjust where the box sits after it is mounted. Most boxes will default to line up with half-inch drywall.
Once the box is mounted, you can install your wall layers. When the final layer is attached, you can adjust the box so it is properly flush according to building codes. It’s really that easy.
Considering Old Work
Doing old work installation is arguably the most important use case for adjustable boxes. They are ideal when you don’t know the substrate thickness of the wall where you are adding the box. If you did know the thickness, you could get an appropriately sized box and go at it. But with that unknown, you need something adjustable.
Installing adjustable boxes for old work is like installing any other box. First, you need to verify that you have an old work box. It should have tabs or braces that go in front of the wall to grip it. Since you can’t attach old work boxes to the studs (at least not reliably), there will be some type of brace on the front and back. Adjustable old work boxes should have screws or sliders that allow you to fit the back clamp to walls of varying thickness.
To install, find your studs so you know where the gaps are in the wall. Measure and cut your hole. Slide the box into place, and then adjust the clamps until you have a tight fit.
For new or old work, all you need is the right adjustable electrical box. Once you find it, you can add boxes wherever they are needed without fear that your box won’t fit.